Minimally invasive techniques are being developed for a variety of surgical procedures. During such procedures, the clinician typically relies on intra-operative imaging to guide instrumentation to a targeted therapy or diagnostic site. This maneuvering is often the most time-consuming portion of the procedure as it can require considerable skill and intuition, particularly when the intra-operative images are two-dimensional images. With the increasing use of minimally invasive techniques, clinical tools are needed that aid a clinician in quickly and accurately localizing a targeted site during a surgical procedure.